Comparative life cycle assessment of lithium-ion batteries for electric vehicles addressing capacity fade

Abstract

Lithium-ion batteries are currently used in electric vehicles (EVs) with many advantages; however, batteries contribute significantly to the life cycle environmental impacts of these vehicles. This article presents a comparative life cycle assessment of two types of batteries – lithium manganese oxide (LiMn2O4) and lithium ion phosphate (LiFePO4) – frequently used in EVs, addressing real-life operational conditions and battery capacity fade. The influence of the location of battery manufacturing and vehicle charging (electricity mix) was also assessed. A life cycle model of batteries in an EV with a service life of 200 000 km (functional unit) was implemented to assess Primary Fossil Energy, Global Warming, Acidification, and Eutrophication impacts. Moreover, the environmental performance of EVs considering both battery types was evaluated. The LiFePO4 battery had better operational performance than the LiMn2O4 one and fewer batteries were needed over the EV service life. Conversely, the life cycle impacts of the LiFePO4 batteries were higher than the LiMn2O4 ones mainly due to higher manufacturing impacts. In countries with a mix based on renewable electricity, the battery production is the most important contributor to impacts, while in countries with electricity mostly from fossil sources, the use phase is the most important. For both battery types and most impact categories, the environmental impacts of EVs were highly dependent on the usage scenario and the electricity mix used for charging.